1. Field of the Invention
The present invention relates to a position detection method, and relates particularly to a position detection method that permits a recording apparatus to identify a position at which to mount an ink tank.
2. Description of the Related Art
Recently, to respond to requests for further increases in image quality, inks having low densities, such light magenta and light cyan, have begun to be employed in addition to inks in the conventional four colors (black, yellow, magenta and cyan). Furthermore, the use of special ink colors, such as red and blue, has been proposed. In such a case, seven to eight ink tanks are separately mounted on an ink jet printer, and for this, a mechanism for preventing the mounting of an ink tank in an incorrect position is required. One arrangement is disclosed in Japanese Patent Laid-Open Publication No. 2004-276291. According to this arrangement, optical paths are formed in the individual ink tanks, and when the ink tanks are mounted correctly, the optical paths are linearly formed, permitting light to be transmitted from light emitting sources to light receiving portions. Thus, when one of the ink tanks is incorrectly positioned and mounted, light can not reach the light receiving portion, and thus the incorrect positioning of the ink tank can be detected. As described above, the arrangement wherein different paths are formed for ink tanks for individual colors is provided in order to identify the position where an ink tank is mounted. However, in this case, depending on the ink colors or ink types, ink tanks having different shapes must be produced. This increases manufacturing efficiency and costs. Furthermore, although this arrangement can detect whether all ink tanks are normally mounted, it can not detect which ink tanks are incorrectly mounted or the positions at which they are mounted.
In another conventional example, an arrangement is proposed whereby a circuit is formed by connecting an electrical contact point for each ink tank to a corresponding electrical contact point on the main body at a location where, for example, a carriage. The signal lines for these circuits are regarded as separate lines for individual mounting positions. In this instance, ink color information for each ink tank is read from the ink tank, and a signal line for turning on an LED is provided as a separate line for each mounting position. With this arrangement, when the color information obtained through reading does not match the mounting position, it can be ascertained that the corresponding ink tank is incorrectly mounted.
Even though the arrangement whereby signal lines are employed separately for individual ink tanks or individual mounting positions enables determination that an ink tank is incorrectly mounted, it increases the number of signal lines in use. And as described above, for the latest types of ink jet printers, one of the trends is an increase in the number of ink types employed in order to improve the image quality, an increase in the number of signal lines increases manufacturing costs. To reduce the number of wiring lines, the employment of a so-called common signal line arrangement, such as a bus connection, is effective. However, neither the ink tank nor the mounting position for it can be identified by employing an arrangement that simply uses a common signal line, such as a bus connection.
Therefore, a position detection method has been proposed whereby by employing a common signal line, light emission control, such as LED control, is performed for mounting positions for a plurality of ink tanks. A light receiving portion is employed to enable identification of the mounting positions of fluid containers, such as the ink tanks. However, according to this connection arrangement, although a light emission signal is output for each of the ink tanks, from this alone it can not be ascertained for which ink tank at which position light is being emitted. In order to avoid this problem, the light emission operation and detection operation can be sequentially performed. That is, during a single detection operation, light emission is performed for an ink tank to identify its position, and subsequently, the succeeding ink tank detection operation is performed.
However, for a recording apparatus mounting ink tanks for multi colors, an extended period of time is required to complete the above described detection processing. For example, for a recording apparatus on which ink tanks are mounted for eight colors, approximately ten seconds is required for the performance of eight repetitious detection operations. As a result, the user is presented with an undesirable printing wait period.